1. Field of Invention
The present invention relates to a system for managing radio modules integrated within a wireless communication device, and more specifically, to a multiradio control system enabled to create an operational schedule for at least one wireless communication medium supported by at least one radio module so as not to exceed an allowed power usage threshold.
2. Description of Prior Art
Modern society has quickly adopted, and become reliant upon, handheld devices for wireless communication. For example, cellular telephones continue to proliferate in the global marketplace due to technological improvements in both the quality of the communication and the functionality of the devices. These wireless communication devices (WCDs) have become commonplace for both personal and business use, allowing users to transmit and receive voice, text and graphical data from a multitude of geographic locations. The communication networks utilized by these devices span different frequencies and cover different transmission distances, each having strengths desirable for various applications.
Cellular networks facilitate WCD communication over large geographic areas. These network technologies have commonly been divided by generations, starting in the late 1970s to early 1980s with first generation (1G) analog cellular telephones that provided baseline voice communication, to modern digital cellular telephones. GSM is an example of a widely employed 2G digital cellular network communicating in the 900 MHZ/1.8 GHZ bands in Europe and at 850 MHz and 1.9 GHZ in the United States. This network provides voice communication and also supports the transmission of textual data via the Short Messaging Service (SMS). SMS allows a WCD to transmit and receive text messages of up to 160 characters, while providing data transfer to packet networks, ISDN and POTS users at 9.6 Kbps. The Multimedia Messaging Service (MMS), an enhanced messaging system allowing for the transmission of sound, graphics and video files in addition to simple text, has also become available in certain devices. Soon emerging technologies such as Digital Video Broadcasting for Handheld Devices (DVB-H) will make streaming digital video, and other similar content, available via direct transmission to a WCD. While long-range communication networks like GSM are a well-accepted means for transmitting and receiving data, due to cost, traffic and legislative concerns, these networks may not be appropriate for all data applications.
Short-range wireless networks provide communication solutions that avoid some of the problems seen in large cellular networks. Bluetooth™ is an example of a short-range wireless technology quickly gaining acceptance in the marketplace. A 1 Mbps Bluetooth™ radio may transmit and receives data at a rate of 720 Kbps within a range of 10 meters, and may transmit up to 100 meters with additional power boosting. Enhanced data rate (EDR) technology also available may enable maximum asymmetric data rates of 1448 Kbps for a 2 Mbps connection and 2178 Kbps for a 3 Mbps connection. A user does not actively instigate a Bluetooth™ network. Instead, a plurality of devices within operating range of each other may automatically form a network group called a “piconet”. Any device may promote itself to the master of the piconet, allowing it to control data exchanges with up to seven “active” slaves and 255 “parked” slaves. Active slaves exchange data based on the clock timing of the master. Parked slaves monitor a beacon signal in order to stay synchronized with the master. These devices continually switch between various active communication and power saving modes in order to transmit data to other piconet members. In addition to Bluetooth™ other popular short-range wireless network technologies include WLAN (of which “Wi-Fi” local access points communicating in accordance with the IEEE 802.11 standard, is an example), Wireless USB (WUSB), Ultra Wideband (UWB), ZigBee (802.15.4, 802.15.4a), and UHF RFID. All of these wireless communication technologies have features and advantages that make them appropriate for various applications.
More recently, manufacturers have also begun to incorporate various resources for providing enhanced functionality in WCDs (e.g., components and software for performing close-proximity wireless information exchanges). Sensors and/or scanners may be used to read visual or electronic information into a device. A transaction may involve a user holding their WCD in proximity to a target, aiming their WCD at an object (e.g., to take a picture) or sweeping the device over a printed tag or document. Near Field communication (NFC) technologies include machine-readable mediums such as radio frequency identification (RFID), Infra-red (IR) communication, optical character recognition (OCR) and various other types of visual, electronic and magnetic scanning are used to quickly input desired information into the WCD without the need for manual entry by a user.
Device manufacturers are continuing to incorporate as many of the previously indicated exemplary communication features as possible into wireless communication devices in an attempt to bring powerful, “do-all” devices to market. Devices incorporating long-range, short-range and machine readable communication resources also often include multiple wireless mediums or radio protocols for each category. A multitude of wireless media options may assist a WCD in quickly adjusting to its environment, for example, communicating both with a WLAN access point and a Bluetooth™ peripheral device, possibly (and probably) at the same time.
Given the large array communication features that may be compiled into a single device, it is foreseeable that a user will need to employ a WCD to its full potential when replacing other productivity related devices. For example, a user may use a multifunction WCD to replace traditional tools such as individual phones, facsimile machines, computers, storage media, etc. which tend to be more cumbersome to both integrate and transport. In at least one use scenario, a WCD may be communicating simultaneously over numerous different wireless mediums. A user may utilize multiple peripheral Bluetooth™ devices (e.g., a headset and a keyboard) while having a voice conversation over GSM and interacting with a WLAN access point in order to access the Internet. Problems may occur when these concurrent transactions cause interference with each other. Even if a communication medium does not have an identical operating frequency as another medium, a radio modem may cause extraneous interference to another medium. Further, it is possible for the combined effects of two or more simultaneously operating radios to create intermodulation effects to another bandwidth due to harmonic effects. These disturbances may cause errors resulting in the required retransmission of lost packets, and the overall degradation of performance for one or more communication mediums.
While a WCD may engage in wireless communication with a multitude of other devices concurrently, in some instances resource constraints may arise, for example, when two or more of the peripheral devices are communicating using different radio protocols. In at least one example scenario, multiple subsystems within a WCD may operate in a substantially concurrent manner. Aside from the previously indicated communication resources, these subsystems may include, for example, at least the operating system of the device as well operator interface elements (e.g., audio, video, inputs, alarming components, etc.). The relatively simultaneous operation of these subsystems may induce a strain on the power source of a portable WCD. As a result, a persistent development limitation restricting the number of features that can be included in a WCD may exist in view of the ability to reliably supply power (e.g., battery technology).
Technology is now emerging to enable a WCD to schedule communications amongst a plurality of modems integrated within the same device, however, this control strategy may not necessarily address power conservation concerns. In actuality, the ability to operate one or more radio modules supporting one or more wireless communication mediums in a relatively simultaneous manner without communication failures due to interference, collisions, etc. may in turn worsen the rate of power consumption and other operational problems. Initially, the ability to operate everything all at once may exceed the specifications of a battery, possibly damaging the battery and maybe even the device. In addition, a WCD may also be impacted by high temperature. Increased power consumption due to multitasking may cause components within the device to overheat. In emerging small form-factor devices, the compact layout does not allow for substantial temperature management resources (e.g., heat sinks or fans), and as a result, the device may automatically reboot or shut down, or may even become damaged from the heat.
What is therefore needed is a system for managing wireless resources in the same device that utilize potentially conflicting wireless communication mediums that is also enabled to account for power limitations. The system should be able to manage the operation of wireless communication mediums so as to avoid conflicts, while also managing the instantaneous power requirements in view of the available power. The system should further be able to adjust to real time power levels by reorganizing power utilization requirements, for example by priority, in order to ensure that both communication failures will be avoided and the power will be reliable.